SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '66ce9f0e8952c635f6baf538abd32441672d13a2953c51be887b7f1d95a6f80d' 
  AND token = 'zwBQLGRl+L6whlq3xE5hV8Kofzmn/hq9LaISYdQ77+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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