SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '9decfbeb49ae37061931adc936e66dde1c85a00d017f3d071e63e5d6a73b481c' 
  AND token = '5hTpCGW31VGCccxScM0KzClo81/u3qR1r62zJ8VijZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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