SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47f1b6c0a194f050a5928c577be386ed78866ff4caf592df35648d5e95803861' 
  AND token = 'YAaGzgScCIH/q0ZRE+WLD6pXpZKxch5ksaor4XNnVXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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