SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dee0c8a92f28c442ef9bc89954ee2a5fe5d1a17b6d4960df989f9665f8c95b93' 
  AND token = '0/LsiUKQOf2G57SZH9kLlTJzsagt6sp0ND0uioTFx5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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