SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2b67b14e5a7c70e4cc2db2565c0170ddfd53de80dec99724940ec276d92295d8' 
  AND token = 'CRnVjs5GexvfFnPozP7aDQViD8icHOmu/5NV4aOCBEQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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