SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea7b829f3877a0b0066c4b895d9d95344442d6693640a729e530814861f4dd8b' 
  AND token = 'Wp8YVIpL0b3xZz4DqcMVzH+SFNpUjJsUcPNEtxmKf0s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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