SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '479e487a1c669a3b6a2a316cbbfb5101991c8ce2c02b8556660372e5b6ee5d63' 
  AND token = 'D7qVHmzEoCI9ik8vW82kIS6j7rf6up3MybFy3+Jr1XU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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