SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ae8f905641e736e7c4af3140362114c10a576e7ebfb63c74c84bcaf1d074c2b' 
  AND token = 'VvgYNPnjs2LPdNpwP+sRqSiXS6xfOhzfeOpmZkvRwK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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