SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a9856deba2b845fe8f583fcbc26dce98a09cf058b99e3ca755bfef91cc03a09d' 
  AND token = '1Wp4wjtPkiPE0VaKfDNrXIgSbFKuTOiWU83HeMV1VfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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