SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd9ac61f497d18b985a9e00aa2fccf3f7d00b12622e2d2f9bdd09486899556af' 
  AND token = 'ibaas74i4eMt2eErNb0xKmMxmu3NTjXtstAnD3Xi5jI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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