SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41e1eee530bbba24d9c58652abb707627d8eb2d31bca4d2fc05998f1b5535944' 
  AND token = 'yndcjAc0H/Ssu8Ro77L6IJEBjxkZuuU/M+fvwbwkcOE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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