SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5138cb35d92f7d5ed44f5d920a2e680e24610f5270893df700d33a551faede1' 
  AND token = 'hNdWotdAjr/9m2wGLgkhXUoMGDd5jxWNFLcEXVPBI3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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