SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0fd12c5d919585a8caae95017df764457d4e89a466f2bfd2922e9fb3140dea56' 
  AND token = 't4k/ABvcDVYrVSatKAzKv3CiU6fcjpjt6fKDgz9PLSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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