SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98eefaf7d5ab7bd069912dc1f558a25ce239bd409283f0f50b523307f8927590' 
  AND token = 'e7G2/AO98Vkva3sUaKKfACyzMuYWw41+gYvFVRJ+uYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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