SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e29e9617c387a54bf3a38df2ef63292096c383f48b9fa3781e9b2758bc31d71' 
  AND token = 'yUMu6OLFtxM0jqb0+mOEznNzwPbT1OWCO+vebuwZ5Do=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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