SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e25d29bb196dbda4e8247dec8ba860cf2e47474bbe84605fd1da205343d0c2d9' 
  AND token = '7Ex6R+QRx/7pdQZdWfwn80jTJYZok2zGIi3mvQm03Ag=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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