SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '932e661feea5f9f0581ebec075a64ee03101a7fce147dea40a015918485efaf8' 
  AND token = 'iYadO8fJ8blL/E/yJMl+BGrbQamQycUwT0CiC1Ekll4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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