SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e86aad059d282f7654a9d36a96ccec26ab849cf9fc8827ff94c6270b917b5606' 
  AND token = 'P7zdbJJzhiZV4rTAMjAlUKH4TjlRAFzyEZqkLwqQMnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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