SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a32428b2cd441f26277b6363c41f79ea1b3718c6e36f9165172c41845ce2f164' 
  AND token = '4HMVxd71gcDluWkkn6IRPYgj/wDyOkhXmTcHy43o1zE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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