SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9282bbc01a7173927898d07a541206a9cd47cadd1f103668f339c4b5d7595fa' 
  AND token = 'ufdFg+z+T20MC2d78lWHYOkJxTwc5mbt6mB3zfpGCk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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