SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ae05eb1a5649ad1934e7516632235af6ee6707d1e861ebea25543e3b200f9f17' 
  AND token = 'XIsj7+sw1KRNmQacb14pFh0KAjCStcGTEJNJzOTg24Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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