SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c598396aaa2773346fdb2a59419785e04d7f787c0f3a2727ccd0101fa1051df' 
  AND token = 'xht+iy90MzHEB127GZ5/bRu42cF1jllgRthc1Ftj8sY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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