SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7be76c50f631215d396b98ef11eff1478edc7ff88154507cb9998cfa9c653d2' 
  AND token = 'ZTaLiIASgkyHHr/FykHWoAaxKGyp3KQCiw6u9xgErmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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