SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b64725b2c19a34f4bf2f1780bd1f5c4002270e6d4641b64f57748af6eed3687c' 
  AND token = 'Cvg+9FwC5+m0hc+T7YHjVJTC0BVJdSrWnWWoPSXPdsA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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