SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7e6545d771b5bbe45f60967d3b97f620beefead58808d5f457870cbb9704c0b9' 
  AND token = 'KhQQZ/VtXgIhA1a9KPskHUfw469GNhYbTBpAlStKF/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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