SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc871fb2bcbb9b9f942a0c02d5d45d3739c468d472f826fc53c2ec08c4d2da6d' 
  AND token = 'ty+G4bBj8PdTbMNhOsGQNhlubA0RzhpyzN/4KGO3jxU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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