SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eb54a506b0205837ba4dc1dbd3f2c0bca44ab006c6304acbe31b719e43103d81' 
  AND token = 'zUsqQZvcf9IchIsn3JsH+w9AciS/dLV9vPrxetYoiFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}