SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0303d4c3a382b48b81132d3b3f7b76cc48972598998993f542d1413042f272ef' 
  AND token = 'hfMtSf8vHKr2FMLONNAxwhZTg6HruT8ZzvKj6rKifKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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