Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '18307afb2d10c54cb58b03f8362422c4ddd2c194794733f52316f3a1b25bf3d2' 
  AND token = '5c/nqdCK+Lb6hX1AOqiOa0Jfo7ZS+3uoHAI2ZeTrZA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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