SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '41d0e1154715170ec7160323330c8ecab66b42c9126f55e920b0201e2a6b450d' 
  AND token = 'VzMCWan+VCpDaBUaAhXykQtD4XIfZTMhs3TWoW2SCyc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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