SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6c92bada5f694d88058f2d9106a80e87c92edb70d6acac213564e08728d0cabe' 
  AND token = 'vVqXEcHNwLEs6l/J0qCeS0tFQfIpz1XvKMNvZzWrBqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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