SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a4013052e7dc581821c8deb07dc2df58f7c0a9f6b99288d60723b364f9d668b2' 
  AND token = 'INZKGmQeEjiwfhTIrqGbtAKvlFhle0RnJRNHBM6QUEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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