SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'e9aa70bc6bd331166bab59a9063555c2b037adcf32da535e60ca01eafa441817' 
  AND token = 'dhlObJG7B6rsjycBxImugMPvrVb9abiNpEZXy/RzIGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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