SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75d1d6384718f95754c944584c99fea9391500d8ba76150869e63ce82a164e4d' 
  AND token = 'nwLZk4379DBYUE+IiaPzuuisM/23rPKzFGIusO3+0YM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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