SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8da8b58fc49d910bb69ad70723b2e8fa19cad0e2ca0e98ff2e81baa2814d4bbe' 
  AND token = '65nr5/DrRxhk6Ij56gtePEamqJPnRTs3rVkMwkhrHzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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