SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ae2b43691d61e40b82550a01302d48d7d4ddb5d9b0d2b30a27027313808eb483' 
  AND token = 'xowIwCuLwms6afUQqmJBncn+Pa0cpLAdWE/XAWbkKAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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