SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86a7be5bdbdfefefb37b0adc9181a138834eb8cf81e2b825121d78268f93ff4c' 
  AND token = 'Yj7G6ex6BdDUVQnby4vJu/rfHzpM0pFSdPNZXejdaso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}