SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73e7c884d97dab8068ce4d2393345fd64f118bf9c1c9c1296157778d11db285b' 
  AND token = 'UiYOIAsmL7OVVgXWuTpVWU4NY4P/nDTorZ2gkjnpXB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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