SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c61420f9c72b8687cb57a3ef4889bbd941f35229de17c4baeac7fb6b490c5858' 
  AND token = 'PxJ4o3TBftkav/vdjLAIqPRw4U9MFM1vd4jOOzu66TI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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