SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99b94c56a8c87910fb1a50f3c5a574d5d7b73dc06f6ff3c76b1b4f680771e961' 
  AND token = 'hngwyV9RHenLZKyBRP7QDC5mrJR9o+32ZvBVr2/M4N4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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