SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e248c7ced168fadabcd49d8d584c7904799226a9ce9b02502e0e03f7999f0d92' 
  AND token = 'NAssymYpgKo7thpYulptNd5ej9G1mTOUIx3kbCajJL0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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