SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57da947559c1aba02e328bccfedc8766965f3ac9268492b8937a062b9aa4b1bf' 
  AND token = 'EfLryFjZ1XY5FzuzWILnM+txcoFhGcBexxtFctkh1i4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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