SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '83958599a30c824900ea15ea227eb751deb505df146b192b0b56c3002abac93c' 
  AND token = 'fgZwp0pjir3eCz0LSQ6ujKOEw3WqgX9Ppj6fycmUuJI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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