SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3b8a1b216c5bf9257eb0ad47cbe1b99e7ad4ee4bb7c581963569a24128cbe4a5' 
  AND token = '/RhY3f1nknoab2AuITghrfs0fqZnKT0gQIZJblJrl+Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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