SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bba3e639ee6d4e5f95a6b9bebd1c296e7c475dea0360932928b799b891b103f' 
  AND token = 'MQACykdnCv8OaT1uZs8AkcFwyO0gxGk036ej1xgo3Vc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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