SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf553da909f09d7565f890ac298408fc14aa7327fe1a603a6048ead6ce678dc9' 
  AND token = 'EqAHapvxt8Jp3XJM+VPeJC167odfud5wO1bj+9MxuOc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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