SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41d2c6c7911a3767c9088e401b3447ccc8a4e29f2f4673aecb79484870a5fbac' 
  AND token = 'w61vkpqoTInSt1BpuHFc2ukxWHQuMdcb9M7fLGGu6mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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