SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c6e37b4d3ec08c89d3d74633af532ac232b7e145db726484f9aa6c74cabb03d' 
  AND token = 'riJrKla4fzrzDq4HqqFAsOXUV1Q//itmE9C8hzjGttc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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