SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e61af594343594fc114478eec5090ba2d041ce991425c4572b77edd75d7cb59' 
  AND token = 'NbOjXVjr5HgVGQzvyEXVEPNEMrOQkuy9xygO1iavLxg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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