SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c112a34cb32795460f112b04f6ec80dbcca26e596dbcace776db2536a4a07f8a' 
  AND token = 'mvgQw4H1hblIDxxKy8nOwnMdxuA9B9soXwyByKBh8sI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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