SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9487491e1a1c73091c042040ece72376f9ca7421bff4f332b26875b103008537' 
  AND token = 'Gk9vogxha682R6IDRVwJFgjgBtM3GH7N/Z7u5UGIjOw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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