SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a14cc991927e834ad8395a5ab12412d051bc17c4155d843f8195a9e87f5f00a' 
  AND token = 'cSFYUV4UpPZDaWfYuAQBqkh+fvHgy8Z8eOnLWQVTKCI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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