SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28c447d6569e7117d4941f0834d3abf9d349af8d1dc18dab4b8ba3270b609fef' 
  AND token = 'Qg8MGpjmMXZjH8nLo0u+xIbjGUEpCPp0opIv5AMjn4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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