SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a069e692ebbad80a9620c08c29b5a8b9bb1fdf28030fd3dafc7f4a1f347b1ab2' 
  AND token = 'Xcyyd2Dg+GDG4AxavbDnkivDD8JaKUL6XjphnzEdDPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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