SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36841fbd4215d8c33ae134ee1ff1252b87fca910bcf685d4d7deb109ffbce136' 
  AND token = 'BGZNhQUrkyqHXfG9Bs8jxjI2T+/Vk1PWgtuSva7fYuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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