SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '470cf08319af2c755c69ba7c382e41a07da15b42c924d1fb6a4218529d9e43d6' 
  AND token = 'NG1inhfVisxlrksIkmKp/H9hrj59/tD4oViAFmIPREU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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