SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dc5ae1d2f756a10304e595f4b27ecefe570b073d17ac7f46f38b6d58a93f5dc6' 
  AND token = 'dfWv/9rL+MD68/xYNM4l1vI4V1xynAl9UGJEJC+lQ38=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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