SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a66e2334415c08c10dd290ec821ebeb87ad75f38490df9d48a55145a05c9cc89' 
  AND token = 'CJyIM+ACj6PVhUCM2/YDZVFh7Dg6JsCFmaZnAFXHrUQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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