SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '403cebd75e2a1da9e7690c58a70f36c39583259a0bd570a1e2183d03f6107808' 
  AND token = 'ZmIkV30ezIhP18jzs+RtfbFo0U2AGSTJnrbIuIotV+0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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