SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5b9945f37fdccfa57f3f2901969045d286cf8f2791d148573542e574c849eb1' 
  AND token = '1mkzD0h9YrUgFTklJu/mOIqCzkbtUKuuEcQa3aoFpG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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