SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0461ac4827cbd90bef49c871a870dd755e4751b726c1624726c1e31194cd5b22' 
  AND token = 'KvlVRE8ibAH/G98Cvmwysv8NPQzgbUO6wFW0ZQtyogI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}