SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '780939d528821cc2b59667fc1203d69cd625754e80a7eba051b7a57efc65d962' 
  AND token = '56Bglyy2ML74FHUPZpVwqIzDf4OYqfVhfDaAuKW8GiE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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