SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '966d4efbe90633faa9055a9bd59c2c81391c3acbc1635e462ad37404a00e475b' 
  AND token = 'qdOoVZhBcSTVn5DzX5ZoM4marz/6YiYKPAUaLMXqzms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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