SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dd8f5b5152997fb85f29002cf50183063865e4929a273e186c9b013ac4788e4' 
  AND token = '9ZdObzv+OfBmPTrUzErKrw1Eg+ZEI9iOKO9mvYDGsWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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