SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '680245ceb9bc369811a9d7554117efcaa9cfa2a574e02cb71a8bc89f789ec97f' 
  AND token = 'iq8uUeiJ4ZAjp21sa5JO5Aalv9sm7WYoi5A9FLbpWS8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}