SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98c1b7579729f6e2bef0f166c91ed2515feef15d7fedd7755933ee4fbd9993fe' 
  AND token = 'GIerx1P1QZ36SvWcNOW1L5HZcN3YyuZVIehqXogj9hE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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