SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '124f32b07ca1a6de812faf6a0ba703ce4cb274bab5e56060428a2f0f59af94ab' 
  AND token = 'tCS8OCubI987qkBVR9bOsLBpsUJEdgZ6v+HnoR90klc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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