SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acd28fb292be884641d1d67a6811c2d02fee9452f72ac25a55a0c89405409c15' 
  AND token = 'Otd7VOl2Sz8IwQSJgC86y8nUEsEoO0MRo1hyzvHyxCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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