SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e289270d02372bae4ad7148f130a36ae35bd562911855ebedd2fc860a25a46da' 
  AND token = 'LSqcK30C548FJk+o5uJrmWdDd0kHAzI/R+6oIxPxndk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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