SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08f6419d5cbb154a2ef3c07bba541c1f5ec7d873bc8283728eca21232fce1a7c' 
  AND token = 'VIVz+qnQYEk1CKYTrYuvswkPInJ5h6hHc+qQjaRyYeg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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