SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57458ff4ef4428495871d6778253b2f7eb00c6ab1100f718dcb2ccaff1edc571' 
  AND token = 'oTyOQrKF29L/VTlrylZd/ZzpxbG6fqiswrlrLYk8aiA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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