SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23c337152908624f27c7042d90b5de084e6648ed3e4b03b85b8d3dc1e571d9df' 
  AND token = 'rw3lRhjtbrkwjVeaq37jojzCeDrVj46wIzfa0ObfkUc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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