SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16dea0d9e136ca13b687d521456080deae49571e569a67e6217204bc0743c032' 
  AND token = '37KRa3wGL/RGbHXa9BrCJeYyA9Aq4PQV04ushhhRUVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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