SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bce66ad2c7f1cbd4a0f89301754691b913405496e3a2ba82a2b4ff55b9003ef0' 
  AND token = 'eucwDaZrfymSvWt+dlf0iUy15Yd5ZPPGtq1WMLk5YTY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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