SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ff397d09af80a0e371f2e90dbe3d0abf75c628eb6e32d9f9d54e7962c96d8c87' 
  AND token = 'hJd1efD9cd3EHCjlcuGeOpukgDU4IfTx+tULPOi3VzY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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