SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85f07ea346b26a6bf69d6cb0d30e68ed3de515ebb94ff08855b8a5db661dbcc1' 
  AND token = 'O5p3MeVJEqQih2Aj+KiMSyY66tCUuuBNwZ+R1eJsRQk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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