SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbec7faa01082735df22e128815f29c5f118c4c7cb4c46a1c17e999bff3c9b56' 
  AND token = 'YufHF1cUjZZOaDsivEdjEngYrnt+N/uR4zjLW4loGww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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