SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df9c79dfe53d93cdee342fb1c1046031083841aa7062fdcffda2c656afb13aed' 
  AND token = 'VfM/qOStTCACe4uKn7ODKsK4b0MV3aZiAQjNFQH91nU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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