SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '633b6a89add3eec3e64e85a146d8f72db6d785fada3398f9a2adebb908c1bbfd' 
  AND token = 'fZE8uZUVboYXcBKjjYFk6Qusd0pDgKHQVmD0iElso+8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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