SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4becdd0fd68b08333fcbde629747164be995f274273d60b6da07111314cc7ff2' 
  AND token = 'EAielbkOPtRyDi7UMYk3H6VOxOfklRYV/OynROSshrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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