SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96df64b216035d074e4f069f8db0668cd86b855cea26c5dd1385dea3e0d06231' 
  AND token = 'ZonsVeNQWNLMFTogl/euOiOE40oxt+J1nLGPiURpFzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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