SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75b2d52a74b2100bde7fbf60f4229b96e8351490ede4c3a27f3b96bd16fc47fe' 
  AND token = 'hriWCfLXCe0fcR3yjWaUwvVzBjXo5jmB/BE7IPEuPpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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