SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5c75557d7e29b923b2ca3124bfe9eccb7e269c98178958285ca1867306054e4' 
  AND token = 'juzC7C2WVqxgIYn/+Kx0VzJBQCA8cq+pudV7qoPCJl8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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