SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79f0e281ce3ace651e0863859520c8ec6b3ff6ddc1f25a3f359d5c2b1cde4960' 
  AND token = '4MEkCiJLjOU/aEzqbPzGkXdccLhZOhVTFMYFqK5go9w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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