SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff38c74adc0f46a6802b9945dbe4adbffa50b3127eae9fa06d5527f7f11801c0' 
  AND token = 'qPzOVLqw5+3QXT2zfx6G/luXJLzcjqKEuGf7Vaoz3PM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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