SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56d85d158fb1c96afc7eff9e2c0b225589a34262ca1a707f18956f00f68141eb' 
  AND token = '491BTHFYaeKZzjGsILjQ3+Dpu+oIUB6Hoq4QCTHbGc8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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