Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec36a92948fb4ce7cd2afbd1a800c1044d1ecca8cd61599a3459f152d8ca51eb' 
  AND token = 'HsMt2ULyO2h0p3FF3dt2jhKUjJE4NGRPBN+fmbcpTj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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