SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daee520ee16bf3bd528e97d57cacc6dd1afd2284001d99e25d0c387b1767d51b' 
  AND token = 'C1wy4Xbj84yeqnODF1acLVZqcbuf5viXVApBYnnMflw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}