SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e330d0d6f52c47385d5a98164338eb34ec76ec7dbdb67b3f00895c239f31edd7' 
  AND token = 's9o+4l155bKJWm8zryxhuvm+1kpKF6ZhBI9cBG/r7zY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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