SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0cff1973928bb1b697c6e3d9255aabaed36ccc0f943de7ef8490731def0af07' 
  AND token = 'jrtVLQAAfMmvpYdHhj0zLuPnXDtHdNABK2CatJxP4fU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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