SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6e94b7eae94fa4a1a52b84ccd62704f8b067ccdca82eba83ce226cdd7cd1b7a6' 
  AND token = 'bHTL9J3z4ZGhmlob+lBJSxIfnATliDSv76VmBvOM3Sw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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