SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5c4c7c09810d0d46ff1a4f331e834444127250e58f95629bca20c604ede9093' 
  AND token = 'TV+IwjvrbN3+3sTpuAtWg4e5If9VUmX6J0tmq6LqtDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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