SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bd693734606b618b4377c9ba049525ceb08d236dc3908a0f7cb37c1bfeab942' 
  AND token = 'm9LBLgxfyreOi296PVHCgTPbZngNmiFxWsjHP5uE/b4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}