SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ce1a6b5751d80c4334a4281384b73dc1f688e1dbc605ca57131fd79d31ce27d' 
  AND token = 'FxbexJWRdMR2ywYla/nvm/B5+iKKji5CY+DJ/ugUPc4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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