SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9e98e487b43531564c240371a7761a3f19c47558bcb0b7d5681d410488d89036' 
  AND token = 'y6lsZ8l7d6Yjz+vf7CviWLgR2Z75Q/iAnzv+CqrjF8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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