SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36c73d2438bf4b610a92093fd94314561c8eebc23b1a828ef95630b19b46f7ea' 
  AND token = '+Xq5glyj8AD6jdzbIDKFEB4CPOTAGjoZh1D+hAdJZYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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