SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b5531cba9b011104333db6f6d76a4dd9d9804aedc3b0a9ebf218668a459df0e' 
  AND token = 'FTiwOPA3FnnOTvR4dPGU6FAKRO0OXrwdTiKgVcOu2Uk=' 
  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"
    }
  }
}