SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ef7c4053bff7c042e2301555a62aeb389b42f9be157a6221f90c34962b541b4' 
  AND token = 'ySLWqtEldx48zKituNw/dOChBwZ/G6bv7Bf2Yg0Rdds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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