SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70eae8a8293027e0a38fe11136d4ba05b864da867db51b04555be9824a80528d' 
  AND token = 'F1HJ1JSWbi0BHlNbU6u4Ptc0HpQTsVlDiCUGexqFUdM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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