SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b54fdccc3dc6367a71ebd9334644ef0ce521402486d4a9d1f529782d91f413d2' 
  AND token = 'ZvKQP+OfhUJwVDXoJqs6hu72H6klNYFgKtchEu9nL+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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