SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36fa4b7e0aae9546183127fe897f38f3ef75ad04d7684408307de5f8694b0896' 
  AND token = 'wSFqE56xdJrVGyBLBuQvvM+Ha/uW1E/JDtezz0h0Cps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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