SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23412cceb325fe30608ea17818ce13e568ad17a9a6cf2294df8658779b2e2c0b' 
  AND token = 'hhNNY3XA/kDRM1cQi48Ois+1pCGGY1hJFvLl4V5QtGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}