SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8358020a73f21a31fbf3fd5a5858169846d43efd91c505d82a3d380c343bf3d7' 
  AND token = 'eAoxB5f4uacp7v7nEHn9bf77B+upApH7VtSMtQYbLUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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