SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '689d8d6e07b2d8e6adff165ecc7ea75dd68b34188e34d522cdd85631277f3e33' 
  AND token = 'hvntifpCPVXieZvFIOzpwMGEO/KrAnh/6XPZgsIaK8o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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