SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e2159baa13af6303ec8c1d392ae24b139fc4aebe05ca3d9b093bccb158d1a12' 
  AND token = 'vVbJk214TU4k04BO9TPSs9TvXl+FS0eMS1MX6r/bvTc=' 
  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"
    }
  }
}