SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba7a7a9183f8326c6b7884d8522d2a9461b71c3eb4791a6c44f0ab12088f1958' 
  AND token = 'Y5fEAKCpg9hP8xh4pLgbAXW/dxHffiu1BFWo48iXOjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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