SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1fea9f1ede99249c25267d88a589b66b65cf14d229c00be3d2c4e1fb3852e727' 
  AND token = 'wtXgedzkZFeQBXFGJlhqdGLmEQtflZgSdSP43cjz1GY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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