SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2e3c21bf0ba4774ec5c7169e830df51be0b51256d3a3274683d13c8c8558bb9' 
  AND token = 'tNuwZ/vGKV2S5lBQJbeC9H6AiVfYKVVNxBcbIk3niSw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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