SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3e53c81e4d94086e8f6f9e5c4b87652194809640026525939e6ca027fcdd5bb0' 
  AND token = 'kMFvONsI6+4ynggzGOBLjXXmo+PXPI0lB7tZ2iE8hso=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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